mattis

I would say it's probably slightly easier to get into than a clinical program. However you still need a competitive application. Most people in my program had good grades and many had some applicable research and/or work-related experience. I'm not sure about transferring an MA in school psychology back to Canada, I would say that depends entirely on how the program is structured and on the requirements of provincial licensing boards. But I'd think an APA accredited PhD in school psych from the US in particular would be transferable across the boards. Keep in mind that if you are looking into US programs that school psychology there is very driven by special education law so there are differences between what a school psych looks like in the US and in Canada.

Make whatever you enjoy the most your plan. Don't just bounce around from one thing to another because your anxiety tells you that you won't be able to do one of them. 

i find that this might have to do with traditions and historical purposes, and, perhaps, some form of political accommodation between the natural sciences and psychology. I study neuropsychology (as close to the "hard science" realm of psychology as there can be!), and came from an undergraduate institution that issued BSc. for psychology programs due to the depth of scientific and empirical rigour the program entails. Yet, at my current graduate institution and my undergraduate institution, the Masters programs in Psychology are distinguished as M.A. over MSc.

Similar to @Jay's Brain, I hold a BSc in Psychology even though my coursework was predominantly social and cognitive, with little bio focus (to compare, a cognitive science degree at this school is consider a BA). My undergrad institute gives out an MA in psych despite being the top research institution in Canada for Psychology (and ranking top 20 globally last I checked). In my current grad institution, I am getting an MSc despite my research's focus being heavily social (though still research intensive)
Honestly, for some schools it seems arbitrary and likely based on tradition. Don't get hung up on the labels of whether its called a "science" or "arts" degree given the interdisciplinary nature of the field. Look at the actual program and what it has to offer.
and that's not even getting into the contentious issue of whether we can even call Psychology a science yet